2002 ISUZU AXIOM front differential

4A1±21 DIFFERENTIAL (FRONT)
4. Remove the cross pin, using a soft metal rod and a
hammer.
425RS043
5. Remove pinion gear.
6. Remove side gear.
7. Remove thrust washer.
Inspection and Repair
Make necessary correction or parts replacement if wear,
damage, corrosion or any other abnormal condition are
found through inspection.
Check the following parts.
1. Ring gear, pinion gear
2. Bearing
3. Side gear, pinion gear, cross pin
4. Differential cage, carrier
5. Thrust washer
6. Oil seal
Ring gear replacement:
1. The ring gear should always be replaced with the
drive pinion as a set.
2. Discard used bolts and install new ones.
Torque: 108 N´m (80 lb ft)3. Tighten the fixing bolts in a diagonal sequence as
illustrated.
415RS016
Reassembly
1. Install thrust washer.
2. Install side gear.
3. Install the pinion gear with thrust washer by engaging
it with the side gears while turning both pinion gears
simultaneously in the same direction.
425RS048

DIFFERENTIAL (FRONT) 4A1±22
4. Install cross pin.

Be sure to install the cross pin so that it is in
alignment with the lock pin hole in the differential
cage.
425RS049
5. Install lock pin. After lock pin installation, stake the
cage to secure the lock pin.
6. Install ring gear and tighten the bolts in diagonal
sequence as illustrated.
Torque: 108 N´m (80 lb ft)
NOTE: Discard used bolts and install new ones.
415RS016

4A1±23 DIFFERENTIAL (FRONT)
Main Data and Specifications
General Specifications
Axle tube TypeIt consists of a duct, a cast iron housing
and an axle tube.
Gear typeHypoid
Gear ratio4.300
Differential typeTwo pinion
Oil capacityliter (US qt)1.25 (1.32) (Differential)
0.12 (0.13) (Actuator Housing: Shift on the fly)
Type of lubricantGL±5 (75W±90)
Axle shaft typeConstant velocity joint
(Birfield joint type and double offset joint)
Hub locking TypeRigid
Torque Specifications
412R200005

DIFFERENTIAL (FRONT) 4A1±24
415R200003

4A1±25 DIFFERENTIAL (FRONT)
Special Tools
ILLUSTRATIONTOOL NO.
TOOL NAME
J±8614±01
Holder; Pinion flange
J±24250
Installer; Oil seal
J±37264
Differential holding
fixture
(Use with J±3289±20
base)
J±3289±20
Holding fixture base
J±42379
Remover; Side/Pinion
bearing
J±8107±2
Adapter; Side bearing
plug
ILLUSTRATIONTOOL NO.
TOOL NAME
J±7817
Installer; Outer bearing
outer race
J±7818
Installer; Inner bearing
outer race
J±8092
Driver handle
J±21777±42
Pilot
J±21777±43
Nut and stud
J±42479±1
Gauge plate

DIFFERENTIAL (FRONT) 4A1±26
ILLUSTRATIONTOOL NO.
TOOL NAME
J±8001
Dial indicator
J±23597±8
Disc
J±23597±1
Arbor
J±6133±01
Installer; Pinion bearing
J±24244
Installer; Side bearing
J±39602
Remover; Outer bearing
ILLUSTRATIONTOOL NO.
TOOL NAME
J±42479±2
Pilot
J±39209
Punch; End nut lock

DIFFERENTIAL (REAR)4A2±3
Diagnosis
Many noises that seem to come from the rear axle
actually originate from other sources such as tires, road
surface, wheel bearings, engine, transmission, muffler, or
body drumming. Investigate to find the source of the
noise before disassembling the rear axle. Rear axles, like
any other mechanical device, are not absolutely quiet but
should be considered quiet unless some abnormal noise
is present.
To make a systematic check for axle noise, observe the
following:
1. Select a level asphalt road to reduce tire noise and
body drumming.
2. Check rear axle lubricant level to assure correct level,
and then drive the vehicle far enough to thoroughly
warm up the rear axle lubricant.
3. Note the speed at which noise occurs. Stop the
vehicle and put the transmission in neutral. Run the
engine speed slowly up and down to determine if the
noise is caused by exhaust, muffler noise, or other
engine conditions.
4. Tire noise changes with different road surfaces; axle
noises do not. Temporarily inflate all tires to 344 kPa
(50 psi) (for test purposes only). This will change
noise caused by tires but will not affect noise caused
by the rear axle.
Rear axle nose usually stops when coasting at
speeds under 48 km/h (30 mph); however, tire noise
continues with a lower tone. Rear axle noise usually
changes when comparing pull and coast, but tire
noise stays about the same.
Distinguish between tire noise and rear axle noise by
noting if the noise changes with various speeds or
sudden acceleration and deceleration. Exhaust and
axle noise vary under these conditions, while tire
noise remains constant and is more pronounced at
speeds of 32 to 48 km/h (20 to 30 mph). Further check
for tire noise by driving the vehicle over smooth
pavements or dirt roads (not gravel) with the tires at
normal pressure. If the noise is caused by tires, it will
change noticeably with changes in road surface.
5. Loose or rough front wheel bearings will cause noise
which may be confused with rear axle noise; however,
front wheel bearing noise does not change when
comparing drive and coast. Light application of the
brake while holding vehicle speed steady will often
cause wheel bearing noise to diminish. Front wheel
bearings may be checked for noise by jacking up the
wheels and spinning them or by shaking the wheels to
determine if bearings are loose.
6. Rear suspension rubber bushings and spring
insulators dampen out rear axle noise when correctly
installed. Check to see that there is no link or rod
loosened or metal±to±metal contact.7. Make sure that there is no metal±to±metal contact
between the floor and the frame.
After the noise has been determined to be in the axle, the
type of axle noise should be determined, in order to make
any necessary repairs.
Gear Noise
Gear noise (whine) is audible from 32 to 89 km/h (20 to 55
mph) under four driving conditions.
1. In drive under acceleration or heavy pull.
2. Driving under load or under constant speed.
3. When using enough throttle to keep the vehicle from
driving the engine while the vehicle slows down
gradually (engine still pulls slightly).
4. When coasting with the vehicle in gear and the throttle
closed. The gear noise is usually more noticeable
between 48 and 64 km/h (30 and 40 mph) and 80 and
89 km/h (50 and 55 mph).
Bearing Noise
Bad bearings generally produce a rough growl or grating
sound, rather than the whine typical of gear noise.
Bearing noise frequently ªwow±wowsº at bearing rpm,
indicating a bad pinion or rear axle side bearing. This
noise can be confused with rear wheel bearing noise.
Rear Wheel Bearing Noise
Rear wheel bearing noise continues to be heard while
coasting at low speed with transmission in the neutral.
Noise may diminish by gentle braking. Jack up the rear
wheels, spin them by hand and listen for noise at the
hubs. Replace any faulty wheel bearings.
Knock At Low Speeds
Low speed knock can be caused by worn universal joints
or a side gear hub counter bore in the cage that is worn
oversize. Inspect and replace universal joints or cage and
side gears as required.
Backlash Clunk
Excessive clunk on acceleration and deceleration can be
caused by a worn rear axle pinion shaft, a worn cage,
excessive clearance between the axle and the side gear
splines, excessive clearance between the side gear hub
and the counterbore in the cage, worn pinion and side
gear teeth, worn thrust washers, or excessive drive pinion
and ring gear backlash. Remove worn parts and replace
as required. Select close±fitting parts when possible.
Adjust pinion and ring gear backlash.

DRIVE LINE CONTROL SYSTEM (TOD) 4B2±102
Diagnosis from Symptom
Troubles that are not indicated by the warning lamp are
listed in the table below. These troubles are caused by the
faults that cannot be detected by the self-diagnostic
function of the control unit.
If this type of trouble is observed, interview the customer
and conduct test runs to reproduce the trouble,
cross-check the reported trouble with the listed
phenomena, and diagnose and analyze the trouble on the
item by item basis.
PhenomenaMajor causeCorrective action
1The tight corner braking is
observed when the vehicle is
subject to full steering.
The standard tires are not used.

The tire pressure is incorrect.

The tires are worn inuniformity.

The transfer or wiring is
imperfect.

The limited slip differential is
failed.Check and recondition the
vehicle according to Chart 1.
2Even if the TOD switch is selected
to the TOD position, the F4WD
mode is not active, resulting in
remarkable rear wheel spin.
The transfer or wiring is
imperfect.

The shift on the fly system is
failed.Check and recondition the
vehicle according to Chart 2.
3
When the TOD switch is
selected to the TOD position,
the drive resistance of the
F4WD system is too large to get
sufficient running speed.

Noised drive line.
The standard tires are not used.

The tires are worn inuniformity.

The transfer or wiring is
imperfect.

The limited slip differential is
failed. Check and recondition the
vehicle according to Chart 1.
4The shift on the fly system (front
axle disconnect) generates gear
noises.
The wiring is imperfect.

The shift on the fly system is
failed.Check and recondition the
vehicle according to Chart 3.
5The braking distance gets long
even when the ABS is active.
The wiring is imperfect.

The ABS is failed.Check and recondition the
vehicle according to Chart 4.
6The transfer does not change to the
low range from the high range.
The transfer or wiring is
imperfect.

The TOD switch is imperfect.

The AT inhibitor switch is
imperfect.
Check and recondition the
vehicle according to chart 5.
7The transfer does not change to the
high range from the low range.
im erfect.

The brake switch is imperfect.

The engine speed signal is
imperfect.

The speed sensor is imperfect.
Check and recondition the
vehicle according to chart 6.
8The transfer stays neutral and the
vehicle does not run.
The transfer is imperfect.Check and recondition the
vehicle according to chart 7.